And to brand-new details on paula broadwell, the other woman in the explosive affair that has rocked washington and brought down america's top spy, he was also the cia director's official biographer. Reporter:40-year-old paula broadwell, high school valedictorian, and harvard graduate, made the media rounds earlier promoting "the new york times" best-selling biography of general david petraeus. Is he awesome or incredibly awesome? He can turn water into bottled water. What! Reporter: Broadwell like petraeus is an avid runner and said she bonded over her six trips to afghanistan to interview him. It was an opportunity for him to interview him on a run. And I thought I'd test him. But he wasoing to test me. You had to be a runner. Reporter: The ironman triathlete explained the importance of these runs. At some point at mile three or four, he started to pick up the pace. I call it the blooming frog approach because you don't know that the water's getting hotter and hotter. Reporter: The two met in 2006 when she later began working on a dissertation about the general, he greed to help. That work turned into her book. In a january interview with don imus she even discussed petraeus' wife. Being married to holly petraeus, a wonderful military spouse. Reporter: Broadwell lived in charlotte, north carolina, with her husband, an interventionist radiologist scott broadwell. She seemed to do it all, kickboxing, wine tasting, foreign affairs and small arms marksmanship. A neighbor tells abc news she received an e-mail from broadwell friday night saying she and her family will be out on a planned vacation for the next several days. George. We're joined by a close

This transcript has been automatically generated and may not be 100% accurate.

David Petraeus Affair: Woman Who Blew the Whistle

Woman at the heart of the investigation is a family friend of Petraeus'.